Author(s): JI, X., SUN, K., Institution: BEIJING INSTITUTE OF SPORTS SCIENCE, Country: CHINA, Abstract-ID: 961

INTRODUCTION:
The function of the gluteus maximus(GM) is very important in sports and daily activities. The GM has complex functions and many exercise methods, if it is not practiced properly, it may cause fatigue and injury in the lower limbs and waist, while the GM is not exercised enough. In order to improve the exercise efficiency of the GM, this paper aims to find the exercise that activatie the GM more while activating the waist and lower limbs less.
METHODS:
Thirteen healthy subjects performed 24 types of no load GM exercises: static gluteal bridge (twice, pre and post the test), dynamic gluteal bridge, shoulder raise gluteal bridge, frog gluteal bridge, one-leg gluteal bridge, side bridge, single-leg side bridge, side-lying hip abduction, kneeling hip abduction (leg up and bend the knee), prone hip extension (legs lift),prone hip extension (frog pose), mid-back extension, kneeling hip extension (leg lift and bent knee), Kneeling hip extension (leg lift straightly), squat, sumo squat, bulgarian squat, lunge squat, front lunge, back lunge, side lunge, knee bend deadlift, straight-leg deadlifts,single-leg deadlifts. Repeat each exercise 5 times for 2s each time; Take a 3min break between exercise. Surface EMG of GM, erector spinae (lumbar,ES), biceps femoris(BF), and vastus lateralis(VL) were acquired. The root mean square (RMS) of each subjects dynamic gluteal bridge was defined as the benchmark, and the RMS of each exercise was divided by the benchmark, which was called normalized RMS of the exercise. Reliability was estimated by the intraclass correlation coefficient (ICC)from RMS of the two static gluteal bridges pre and post the experiment to exclude the influence of fatigue. One-way ANOVAs was used to test the differences between the normalized RMS and activation ratios of each exercise and the gluteal bridge.
RESULTS:
The ICC of RMS values of the two static gluteal bridges pre and post the experiment is 0.83, which indicate that the GM had no fatigue during the test, and the results were reliable. The normalized RMS of GM of each exercise ranged form 0.70 to 2.83, and the prone hip extension (frog pose) was maximal (2.83±1.48, P=0.000). The GM/ES activation ratio ranged from 0.29 to 1.93, the kneeling hip abduction (leg up and bend the knee) was maximal (1.93±1.87, P=0.000), and the prone hip extension (frog pose) was the third (1.16±1.00, P=0.212). The activation ratio of GM/VL was 0.33 to 6.63, and the prone hip extension (frog pose) was maximal (6.63±4.42, P=0.000). The activation ratio of GM/BF was 0.54 to 1.63, the hip abduction was maximal in all the lying exercise (1.63±1.70, P=0.173), and the fifth in the prone hip extension (frog pose) (1.26±0.63, P=0.910).
CONCLUSION:
Among the 24 common GM exercises, the prone hip extension (frog pose) has the maximal activation degree for GM, and lower activation degree of erector spinae, vastus lateralis and biceps femoris.It will develop the GM More specialized, and cause less fatigue on nearby muscles.